Computers and other electronic devices generally require a medium in which digital data can be stored and retrieved. Data storage devices come in a variety of forms and serve a variety of purposes. These devices can be broken down into two general categories: solid state and non-solid state storage devices.
Non-solid state devices are devices that contain moving parts. Some typical non-solid state storage devices are hard disk drives, CD/RW drives and disks, DVD/R/RW drives and disks, floppy disks, tape drives and probe memory devices. These storage devices move one or more media surfaces and/or the associated data head relative to one another to position the data head relative to a desired location or area on the media. The data is then written to or read from this data location. In disk drives for example, data is stored on a disk that rotates at an essentially constant velocity. By moving the head over the rotating disk, all memory locations or sectors of the disk can be accessed.
Solid state storage devices differ from non-solid state devices in that they typically have no moving parts. Solid state storage devices may be used for primary storage of data for a computing device, such as a personal computer, workstation computer, or server computer. Another example of a solid state storage device is flash memory, such as used in a Compact Flash Memory Card. Compact Flash Memory Cards are used primarily for easy and fast information storage in devices such as digital cameras, home video game consoles, smart phones, and personal digital assistants.
Conventional solid state storage devices store logical block address (LBA) blocks in pages of an erasure block. When an erasure block is to be updated, every page therein must be invalidated and entirely rewritten, including both unaltered and altered (e.g., new or modified) data.